too much battery power???

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JHZR2

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Hi,

Can you ever have too much battery power from a single battery in an automotive application?

Say your car is specced for some small, 500CCA battery, and you shoehorn in a huge group 49 diesel battery at over 1000CCA... is this bad?

If your car is OE with a 700CCA battery and you put in an 800 or 850, will ti harm stuff? Will too much power go through the starter, or will it always only draw enough to spin at one constant speed, and thus always be OK?

I dont want to harm the system by putting in too many CCA, CA, or too big of a battery (provided that it will fit), but see that the reserve capacity and added starting power is nice to have, especially in the wintertime.

Any suggestions?

Thanks,

JMH
 
I installed an Oddyssey PC1200 drycell battery in my car about 30k miles ago, and have no problems what so ever. Oddyssey claims that this battery has 1200 CCA during the first 5 seconds of startup.
 
As long as it's a 12V battery it will always (for a given level of charge, of course) put the same amount of amperage into a given load.

So, the starter will still spin at the same speed. It can just spin at that speed for longer, the battery will not be depleted as quickly.

Liken it to adding a bigger air tank to your compressor but leaving the pressure regulator set where it's at.
 
I agree with Donald 100% You could have a 1,000,000,000 CCA battery and it won't hurt the starter at all as long as the battery is charged to around 12V. A larger battery may allow for more power loss inside the battery - depending on what the construction is. Whenever you discharge or charge the battery the chemistry and the plates dispell some heat and possibly electrolyze water - consuming energy. The larger battery you have, the larger the potential for this to occur. If you could grab some datasheets for the battery it could tell you how inefficient the battery is.
 
I agree totally with Donald and mjo. In order to get more current capacity out of a battery of the same physical size, many of the internals will have to be made in a way that could make them less rugged. So, the battery might not last as long. Were it not for that, more CCA is better even if unneeded.
 
I replaced the battery on my old 79 GMC Pickup (750 CCA I think, stock was 600) and after the truck sat for about 8 hours at -40C I went out to start it and I exploded a solid chunk of metal right off the starter housing into the flywheel. I replaced the starter the next day, but that little piece of metal stayed in the flywheel and every once in a while got into a weird position and would grind for about 10 minutes at a time. So yeah, you can have too much juice.
 
No you cannot have too much battery power. But you really only need to by the CCA that your car came with. Batteries that are the same size but have more CCA have weaker plates as they do various things to the plates to get more surface area and most of that makes the plates weaker.
 
Will not hurt anything.
Would help to go upgrade a bit from spec.
Manufacturer usually has minimum required put in.
Nice to know a battery with higher RC in case of Alt. failure.
 
If your car won't start a big battery can cook the starter if you crank it too long.
 
If you live in a cold (and especially in a really cold) climate, more CCA's will DEFINITELY result in quicker and easier cold weather starts, and sometimes in a start when a battery with less CCA's won't start the vehicle. I've always lived where it gets to -30 below or colder every winter. Sometime at that temp, in a given vehicle, a battery with 25-50% more CCA's than the stock battery makes the difference between a start and a non-start. When its that cold, the battery gets so cold that it looses some of its power (and thus looses some of its CCA's), and sometimes a lot of its power, and the engine and oil get so cold that the engine's hard to turn over. In that situation, the extra CCA's are useful (and sometimes absolutely needed) unless the vehicle's in a garage or is outside and has both a block heater and a battery warmer. When its way below zero is the worst time for a vehicle to not start, particularly if it results in your being stranded in the boonies and you do not have help nearby. For example, I used to big game hunt in the mountains of Montana, often far from assistance, when it was -10 or more below, and a nonstarting vehicle can be a death warrant in a situation like that. I always run a battery with at least 25% more CCA's than the stock battery. The extra CCA's cost very little, don't harm anything, do NOT result in the battery wearing down faster, in fact they result in the battery turning the engine over longer in cold weather, and are valuable insurance.
 
Batteries with more CCA's can put out more power and won't hurt anything. The lower the battery's internal resistance the more power it can put out. The internal resistance is a limiting factor.

A scenario would be starting and battery voltage drops to say 10V with that load on it. But maybe a battery with higher CCA's and lower internal resistance the voltage only drops to 11V when starting. That results in more power for the starter.

Now if one were using one of those 12/16V batteries you can see even more power would be consumed by the starter.

P=I*V
grin.gif
 
What happens to your charging system,(alternator) when and oversized battery is installed? Does the charging system have to work overtime to replace the battery power that is being used?
This is something that I've always wanted to know.
 
there shouldn't be any problem with an oversize battery under normal conditions. its charging the battery to a particular voltage. the amount of energy lost during a start is going to be the same for a higher CCA battery. the charging system has to put back the same amount regardless of battery size. the battery might have slightly different characteristics (more/less internal resistance) but certainly within the limit of the charging system.
 
IMO there cannot be 'too much' battery power. My '77 Chev 454 pickup requires all the cranking amps a battery can muster, especially when hot (the dreaded 'heat soak' scenario!).

Sure wish I could put a regular-size battery in my '95 Civic!!! The type 51/R belongs on a lawn mower!
 
oversize batteries wont tax an alternator anymore than a normal batery would. the sum of all alternator input to the battery is the sum of all electrical load output from the battery.

example: if youre car takes 4 seconds to start and the starter draws 100 amps for 4 seconds, then the alternator must put back this energy no matter what size the battery is.
you can have a little honda car battery or some big dumptruck battery. its still 100 amps for 4 seconds.
 
That's true for normal starts but a fully discharged large storage battery can be a bit of a charging black hole. On the other hand, alternators do have current limiting so the charge should just take longer than a smaller battery without hurting anything
 
the busted starter was not the battery.
either timing was off or it was damaged before.
i run 2 group 24 agm ups batts in one of my cars in paralel for my ham gear.combined they would rate around 1500cca.
strapped together with 2 ga and 2 ga to the block and starter.
never a problem.they can be below 10.5v and it will still start.the alt hates that though.it will whine/scream and smell like hot varnish while recharging from such an event.at least delco 94a is cheap and easy to rebuild.and a 5 min job to change.
 
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